heatmappy

Draw image and video heatmaps in python

Image

Video

Install

pip install heatmappy

Requirements

• matplotlib
• moviepy
• numpy
• Pillow
• PySide (optional: up to ~20% faster than Pillow alone)

Examples

Given some points (co-ordinates) and a base image

from heatmappy import Heatmapper

from PIL import Image

example_points = [(100, 20), (120, 25), (200, 50), (60, 300), (170, 250)]
example_img_path = 'cat.jpg'
example_img = Image.open(example_img_path)

Draw a basic heatmap on the PIL image object

heatmapper = Heatmapper()
heatmap = heatmapper.heatmap_on_img(example_points, example_img)
heatmap.save('heatmap.png')

Draw a reveal heatmap, given the image path

heatmapper = Heatmapper(opacity=0.9, colours='reveal')
heatmap = heatmapper.heatmap_on_img_path(example_points, example_img_path)
heatmap.save('heatmap.png')

Draw a video heatmap

Input points are in the form (x, y, t) where t is in milliseconds.

example_vid = os.path.join('assets', 'some_video.mp4')
example_points = [(100, 100, 25), (112, 92, 67), (17, 100, 36)]

img_heatmapper = Heatmapper()
video_heatmapper = VideoHeatmapper(img_heatmapper)

heatmap_video = video_heatmapper.heatmap_on_video_path(
    video_path=example_vid,
    points=example_points
)

heatmap_video.write_videofile('out.mp4', bitrate="5000k", fps=24)

Heatmap config

The following options are available (shown with their default values):

heatmapper = Heatmapper(
    point_diameter=50,  # the size of each point to be drawn
    point_strength=0.2,  # the strength, between 0 and 1, of each point to be drawn
    opacity=0.65,  # the opacity of the heatmap layer
    colours='default',  # 'default' or 'reveal'
                        # OR a matplotlib LinearSegmentedColorMap object 
                        # OR the path to a horizontal scale image
    grey_heatmapper='PIL'  # The object responsible for drawing the points
                           # Pillow used by default, 'PySide' option available if installed
)

video_heatmapper = VideoHeatmapper(
    heatmapper  # the img heatmapper to use (like the heatmapper above, for example)
)

Provided colour schemes

default

reveal

Coming soon

• Can specify different point size for each point plotted.

License

MIT License.